Ada is a village in Hardin County, Ohio, United States. The population was 5,582 at the 2000 census. In 2006, the city's population was estimated at 5,841. The Wilson Sporting Goods NFL football manufacturing facility is located in Ada, and is the only football manufacturing facility in the United States. The National Arbor Day Foundation has qualified Ada as a Tree City USA. In 1817, The Ohio Shawnee Native American tribe signed the Treaty of Fort Meigs to receive reservation land at Hog Creek near Ada.